1. Field of the Invention
The invention relates to a machine, a module and a method for electrochemically machining a workpiece, in particular a gas turbine component.
2. Discussion of Background Information
Electrochemical machining (ECM) is a forming machining method for machining of workpieces that can be used advantageously, in particular, in the machining of complex surface shapes and/or materials that are difficult to machine. The method uses the anodic oxidation of the material to be machined, wherein a working electrode is arranged at a distance from the surface to be machined, an electrolyte is provided in the gap between the surface to be machined and the electrode and, as a result of an electric potential being applied between the electrode and the workpiece to be machined, the material of the workpiece is dissolved by anodic oxidation and goes into the electrolyte. This results in a removal of material, which is dependent on the potential relationships in the machining gap. These relationships, in turn, are influenced by the gap width, such that a three-dimensional shape of the working electrode, having correspondingly differing distances of the working electrode from the surface to be machined, results in a material removal that is dependent on shape. The shape of the working electrode can thus be imposed, or reproduced, on the machined surface.
Electrochemical removal of material can be performed not only continuously, but also in pulsed form, in which case, instead of a continuous flow of current being set, a multiplicity of current pulses are executed in succession. Such a method is also referred to as PECM (“pulsed electrochemical machining” or “precise electrochemical machining”)
Typically, the working electrodes are moved back and forth in a sinusoidal rhythm. In this case, in the removal of the electrode, the speed should be selected so as to be only of such a magnitude that no cavitations are produced between the working electrode and the workpiece. Cavitations should be avoided as far as possible, since the workpiece is damaged by metal particles being separated out locally. Moreover, these metal particles then present in the gap can cause a short circuit between the tool and the workpiece.
In view of the foregoing, it would be desirable to improve the electrochemical machining of a workpiece, in particular of a gas turbine component.